Mower cutting unit

Abstract

An inproved cutting unit specially suited for grooming turf includes a frame supporting a conventional horizontally mounted driven reel having a number of spirally arranged blades. The cutting unit is supported on the ground by front and rear rollers. The front roller is a slotted expunger roller having numerous annular slots along its axis. Immediately behind the expunger roller is mounted a knife roller which includes numerous vertically oriented knife blades aligned with the circular slots of the expunger roller. As the expunger roller rolls along turf, horizontally lying plant material is pulled or puckered up by the expunger roller into the circular slots. The knife roller, driven at a high rate of speed about its own axis, pulls up and slices through the pulled up plant material. The expunger roller is mounted to the frame while the knife roller is pivotally mounted to the expunger roller to allow the height of the knife roller to be varied without changing the height of cut or the distance between the knife and expunger roller axes.

It is claimed: 
     
       1. A cutting head for use with a turf cutting unit having a frame, the cutting head comprising: a generally horizontal slotted expunger roller for mounting to the frame for rotation about an expunger roller axis, an outer expunger roller surface and a plurality of vertically disposed annular slots located in a predetermined axial pattern along said expunger roller, said slots dividing said expunger roller surface into a plurality of expunger roller surface segments; and   a cutter, including a plurality of cutting edges aligned with said annular slots, rotatably drivenly mounted adjacent and behind said expunger roller with at least a portion of said cutting edges passing within said annular slots;   whereby horizontally disposed plant matter is raised up into said annular slots as said expunger roller surface segments roll over said plant matter to allow said cutter to cut said raised up plant matter.   
     
     
       2. The cutting head of claim 1 wherein: said cutter includes a knife roller including a knife roller axis and a plurality of knife blades, comprising said cutting edges, positioned along said knife roller axis in said predetermined axial pattern; and further comprising:   means for rotating said knife roller and said knife blades therewith about said knife roller axis; and   means for mounting said knife roller adjacent and behind said slotted expunger roller so said knife blades pass through said annular slots as said knife roller and knife blades therewith are rotated about said knife roller axis by said rotating means.   
     
     
       3. The cutting head of claim 1 wherein said expunger roller is a front support member of the cutting unit. 
     
     
       4. The cutting head of claim 1 wherein said predetermined pattern is a regular pattern so said slots are evenly spaced along said expunger roller. 
     
     
       5. The cutting head of claim 2 wherein a plurality of said knife blades pass through each of said slots. 
     
     
       6. The cutting head of claim 5 wherein said cutting edges of said knife blades are radially directed. 
     
     
       7. The cutting head of claim 2 wherein: said knife roller mounting means includes a link pivotally connecting said knife and expunger rollers, said link adapted to pivot about said expunger roller axis, and a knife roller height adjuster mounted to the cutting unit frame and operably coupled to said link to raise and lower said knife roller as said link and knife roller therewith pivot about said expunger roller axis so the centerline distance between said expunger roller and said knife roller axis remains constant.   
     
     
       8. The cutting head of claim 7 wherein said knife roller height adjuster includes a link at each end of said knife roller. 
     
     
       9. The cutting head of claim 8 wherein said knife roller height adjuster is connected directly to said link. 
     
     
       10. The cutting head of claim 1 wherein said expunger roller comprises: a main shaft; and   a plurality of expunger discs each having a central opening sized for mounting over said main shaft, an outer diametral surface, an inner diametral surface and a sidewall connecting said outer and inner diametral surfaces, said outer diametral surfaces defining said expunger roller surface segments and said inner diametral slots.   
     
     
       11. The cutting head of claim 1 wherein said circular slots include an outer region adjacent said roller surface segments having inwardly sloping sides. 
     
     
       12. The cutting head of claim 11 wherein said inwardly sloping sides are arcuate. 
     
     
       13. The cutting head of claim 12 wherein said arcuate inwardly sloping sides have a circular contour. 
     
     
       14. The cutting head of claims 2 or 22 wherein said knife roller comprises a plurality of knife roller segments mounted adjacent one another. 
     
     
       15. The cutting head of claim 14 wherein said knife roller includes a knife shaft over which said knife roller segments are fixedly mounted for rotation with said knife shaft. 
     
     
       16. The cutting head of claim 14 wherein said knife blades are generally radially directed. 
     
     
       17. The cutting head of claim 16 further comprising rotary offset means for fixedly positioning said knife roller segments to one another with a rotary offset so said radially directed blades are arranged in a spiral along said knife roller axis. 
     
     
       18. The cutting head of claim 17 further comprising a plurality of said knife blades at each said knife roller segment. 
     
     
       19. The cutting head of claim 17 wherein said rotary offset positioning means includes axially extending pins extending from one side of said knife segment at a chosen position relative to said radially directed blades and complementary openings formed in a second, opposite side of said knife segments, said pins and openings being offset a chosen rotary angle for each said knife segment so said radially directed blades are in said spiral along said knife axis. 
     
     
       20. A cutting head for use with a cutting unit including a frame, the cutting head comprising: a slotted expunger roller, constituting a front support member for the cutting unit, for mounting horizontally to the frame and having an expunger roller axis, an outer expunger roller surface and a plurality of vertically disposed annular slots located in a predetermined axial pattern along said expunger roller, said slots dividing said expunger roller surface into a plurality of expunger roller surface segments;   a knife roller including a knife roller axis and a plurality of knife blades arranged along said knife roller in said predetermined axial pattern, said blades positioned to pass through said slots;   means for rotating said knife roller and said knife blades therewith about said knife roller axis;   means for mounting said knife roller adjacent and behind said slotted expunger roller so said knife blades pass through said circular slots as said knife roller and knife blades therewith are rotated about said knife roller axis by said rotating means; and   said knife roller mounting means including a link pivotally connecting said knife and expunger rollers, at each end of said rollers, said link adapted to pivot about said expunger roller axis, and a knife roller height adjuster mounted to the cutting unit frame and operably coupled to said link to raise and lower said knife roller as said link and knife roller therewith pivot about said expunger roller axis so the centerline distance between said expunger roller and said knife roller axis remains constant;   whereby horizontally disposed plant matter is pulled up into said circular slots as said expunger roller surface segments roll over said plant matter so said rotating knife blades cut said pulled up plant matter.   
     
     
       21. A cutting head for use with a turf cutting unit having a frame, the cutting head comprising: a generally horizontal slotted expunger roller for mounting to the frame for rotation about an expunger roller axis, an outer expunger roller surface and plurality of vertically disposed annular slots located in a predetermined axial pattern along said expunger roller, said slots dividing said expunger roller surface into a plurality of expunger roller surface segments; and   a cutter, including a plurality of cutting edges aligned with said annular slots, rotatably drivenly mounted to the frame adjacent and behind said expunger roller;   whereby horizontally disposed plant matter is raised up into said circular slots as said expunger roller surface segments roll over said plant matter to allow said cutter to cut said raised up plant matter.   
     
     
       22. The cutting head of claim 21 wherein said cutter includes a knife roller including a knife roller axis and a plurality of knife blades, comprising said cutting edges, positioned along said knife roller axis in said predetermined axial pattern. 
     
     
       23. A turf cutting unit comprising: a frame; and   a cutting head comprising: a slotted expunger roller, mounted horizontally to the frame for rotation about an expunger roller axis, including a plurality of vertically disposed annular slots; and   a cutter, including cutting edges aligned with said annular slots, rotatably drivenly mounted to the frame adjacent and behind the expunger roller;     whereby plant material is raised up by the expunger roller and cut by the closely following cutter.   
     
     
       24. The cutting unit of claim 23 wherein the cutter includes radially extending knife blades on which said cutting edges are formed. 
     
     
       25. The cutting unit of claim 23 further comprising a bed knife and a cutting reel mounted to the frame, the cutting reel drivingly coupled to the cutter. 
     
     
       26. The cutting unit of claim 23 further comprising a rear roller mounted to the frame to support the cutting unit at one end opposite the expunger roller. 
     
     
       27. A cutting head, for mounting to the frame of a turf cutting unit, comprising: a slotted expunger roller, mounted horizontally to the frame for rotation about an expunger roller axis, including a plurality of vertically disposed annular slots; and   a cutter, including cutting edges aligned with said annular slots, rotatably drivenly mounted to the frame adjacent and behind the expunger roller; whereby plant material is raised up by the expunger roller and cut by the closely following cutter.     
     
     
       28. A grass cutting head comprising: spaced-apart means, defining channels therebetween, for lifting grass, situated within the channels and tending to grow other than vertically, into said channels as said grass lifting means moves over the grass; and   a cutter, including cutter elements operating within the channels, for cutting the lifted grass.   
     
     
       29. The grass cutting head of claim 28 wherein the grass lifting means includes a slotted roller. 
     
     
       30. The grass cutting head of claim 28 wherein the cutter includes a knife roller having radially directed knife blades passing through said channels.